The present invention is directed to winding tubes, and more particularly to a reusable winding tube in which the fibers or filaments are more easily removed from the peripheral groove which carries the transfer bunch once the package has been emptied.
In conventional automatic winding operations, yarn is wound onto a cylindrical paper tube. One end of the paper tube includes a peripheral groove cut into the surface thereof. The peripheral groove is divided into two arcuate portions. The greater arcuate portion (approximately 270.degree.) is wider and referred to as the lead-in portion, while the smaller (approximately 90.degree.) arcuate portion (locking portion) is narrower and locks one or more of the initial strands of yarn therein during the initial few turns of the automatic winding operation. These strands are hereinafter and commonly referred to as the "transfer bunch." The completed yarn package is removed from the winding machine, and stored or shipped for further processing. During the further processing, the yarn is then removed from the yarn carrier.
When the yarn is removed from the package, the last few strands of the transfer bunch remain in the lead-in and locking portions of the groove. Because of the construction of the paper tubes, it is very difficult to remove these remaining strands of fibrous or filamentary material from the grooves. Previous attempts to remove these strands have included vacuum stripping, cutting of the strands, or a combination of both. Neither technique is satisfactory, because vacuum stripping simply does not remove all the fibrous or filamentary material. Cutting the bunch generally results in damage to the surface of the tube making it unsuitable for further use. Such damage occurs when the laminates of the paper tube are niched, cut, or otherwise interrupted. Use at high speeds then tends to cause delamination.
As a result, paper winding tubes are generally not reusable. There have been some attempts to reuse the tubes by providing the transfer grooves at each end of the tube, so that the tube can be reused at least once. However, often the tube is otherwise damaged during the automatic doffing and emplacement operations which substantially eliminates the reuse of the paper tubes. Conventional paper tubes are relatively expensive (50.cent. to $1.50 apiece) and hundreds of thousands per year are used by typical yarn manufacturers. Thus the cost of non-reusable yarn carriers is extremely high.
Merely the replacement of paper tubes with a stronger material such as a polymeric material or aluminum is not an obvious solution. First the transfer groove cannot satisfactorily be molded or machined in the wall of a polymeric or metallic tube. Secondly merely a change of material does not solve the problems created by the necessity to clean the starting bunch groove, as it is still not easy to vacuum the groove, and utilizing a knife will still damage the surface of the tube so that it cannot be reused. While the use of polymeric material or metallic material such as aluminum is a first step toward an improved tube, it has been found that some technique for the cleaning of the transfer groove must be provided in order to achieve a reusable winding tube.
Examples in the prior art of separable yarn carriers are illustrated in the U.S. Pat. Nos. to Chaffin No. 1,991,880; Moss No. 2,837,297; and Underwood No. 3,971,526. However, none of these yarn carriers are for automatic winding operations or for the purpose of solving the problem of removing residual fibers and filaments from a transfer bunch.
In the broadest aspect of the present invention then, the tube is made reusable by the combination of selecting an appropriate material and a unique fabrication technique. The tube is formed of a polymeric or metallic material in two separable parts, i.e. the main hollow tube portion and a removable end cap. A peripheral groove of unique shape is formed between confronting walls of the end cap and hollow tube to receive the transfer bunch during the automatic winding operation. After the yarn package is emptied the end cap is removed or partially removed from the hollow tube portion, the fibers or filaments vacuumed or stripped away, and the end cap replaced. The yarn carrier is then ready for reuse.
In its more specific aspects the reusable winding carrier of the present invention includes a hollow tube having an outer, substantially cylindrical surface adapted to carry a filamentary or fibrous yarn thereon. The end cap includes an outer substantially cylindrical surface generally of the same radius as the outer surface of the hollow tube. The end cap and hollow tube include mating threads or other releasable attachment means for releasably mounting the end cap on at least one end of the hollow tube. It is possible that both ends of the hollow tube may include releasable end caps to make the winding tube last even longer.
A peripheral groove is formed between the hollow tube and end cap encircling the yarn carrier. The groove is formed with a relatively narrow locking portion extending around a minor portion (approximately 90.degree.) of the periphery of the tube and a relatively wider lead-in portion extending around the remaining major of the periphery. The lead-in portion guides the first few turns of the transfer bunch into the locking groove. The wider and narrower portions of the peripheral groove are formed by molding recesses into or chamfering the confronting walls of the hollow tube and/or end cap during the fabrication of the components.
The construction of the present invention combines the benefits of overall economy for the plant; facilitates cleaning of the transfer groove; allows replacement or refurbishment of worn or damaged portions of the winding tube assembly; and minimizes the chance of damage to the tube during shipment and use.
It is therefore an object of the present invention to provide a reusable yarn carrier or winding tube by facilitating the cleaning of the transfer groove.
It is another object of the present invention to provide a winding tube of the type described in which the end portion of the winding tube is removable from the main body portion.